John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Narcolepsy is a chronic disease of the central nervous system. Excessive daytime sleepiness (EDS) is the main symptom and is present in 100% of patients with narcolepsy. Other primary symptoms of narcolepsy include:
loss of muscle tone (cataplexy),
distorted perceptions (hypnagogic hallucinations), and
Additional symptoms include disturbed nocturnal sleep and automatic behavior (patients carry out certain actions without conscious awareness). All of the symptoms of narcolepsy may be present in various combinations and degrees of severity.
Narcolepsy usually begins in teenagers or young adults and affects both sexes equally. The first symptom to appear is
excessive daytime sleepiness, which may remain unrecognized for a long time in that it develops gradually over time. The other symptoms can follow
excessive daytime sleepiness by months or years.
How common is narcolepsy?
The prevalence of narcolepsy is similar to that of Parkinson's disease and multiple sclerosis. In the United States, the National Institute of Neurological Disorders and Stroke estimates narcolepsy affects one in every 2,000 people. However, in some countries (for
example, Israel), the prevalence of narcolepsy is much lower (one per 500,000) while in other countries (for
example, Japan), it is much higher (one per 600). The American Sleep Association estimates that approximately 125,000 to 200,000 Americans suffer from narcolepsy, but only fewer than 50,000 are properly diagnosed.
Narcolepsy often remains undiagnosed or misdiagnosed for several years. This may occur because physicians do not consider the diagnosis of narcolepsy frequently enough. They may think of narcolepsy only in people who have the main symptom of
excessive daytime sleepiness. Narcolepsy may not be considered in the evaluation of patients who come to doctors complaining of fatigue, tiredness, or problems with concentration, attention, memory, and performance, and other illnesses (seizures, mental illness, etc.).
What causes narcolepsy?
Advances have been made in the last few years in determining the cause of narcolepsy. The newest discovery has been the finding of abnormalities in the structure and function of a particular group of nerve cells, called hypocretin neurons, in the brains of patients with narcolepsy. These cells are located in a part of the brain called the hypothalamus and they normally secrete neurotransmitter substances (chemicals released by nerve cells to transmit messages to other cells) called hypocretins.
Abnormalities in the hypocretin system may be responsible for the daytime sleepiness and abnormal REM sleep found in narcolepsy. (See the section below on sleep laboratory tests for a discussion of
REM sleep.)
Experiments in dogs and mice with narcolepsy point to an abnormal hypocretin system as a cause for the development of their narcolepsy. People with narcolepsy have been found to have a markedly decreased number of hypocretin nerve cells in the brain. They also have a decreased level of hypocretins in the cerebrospinal fluid (the fluid that surrounds the brain and the spinal cord).
Narcolepsy is associated with a specific type of human leukocyte antigen (HLA). HLAs are genetically determined proteins on the surface of
white blood cells. They are a part of the body's immune (defense) system. The finding of a very high HLA-association in narcolepsy led to the proposal that narcolepsy is an
autoimmune disease, similar to other HLA-associated diseases such as multiple sclerosis and ankylosing spondylitis.
It is theorized that an autoimmune reaction causes the loss of nerve cells in the brain in patients with narcolepsy. The environment (for example, infection or trauma) might trigger an autoimmune reaction where normal brain cells are attacked by the body's own immune system. As a result, the neurons are damaged and ultimately destroyed, and they and their neurotransmitter chemicals disappear. Whether narcolepsy is an autoimmune disease remains to be proven.
The role of heredity in humans with narcolepsy is not completely understood. No consistent pattern of heredity has been recognized in families so far. It is estimated that relatives of patients with narcolepsy may have a higher predisposition to develop narcolepsy or sleep-related abnormalities, such as increased daytime sleepiness, increased REM sleep, or others. In dogs with narcolepsy, the disease is inherited in a predictable pattern. In these animals, the narcolepsy is caused by a mutation in a particular gene that is normally responsible for producing a receptor (binder) in the brain for the hypocretin neurotransmitter.
Stress occurs when forces from the outside world impinge on the individual. Stress is a normal part of life. However, over-stress, can be harmful. There is now speculation, as well as some evidence, that points to the abnormal stress responses as being involved in causing various diseases or conditions.
Depression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. The principal types of depression are major depression, dysthymia, and bipolar disease (also called manic-depressive disease).
Sleep apnea is defined as a reduction or cessation of breathing during sleep. The three types of sleep apnea are central apnea, obstructive apnea (OSA), and a mixture of central and obstructive apnea. Central sleep apnea is caused by a failure of the brain to activate the muscles of breathing during sleep. OSA is caused by the collapse of the airway during sleep. OSA is diagnosed and evaluated through patient history, physical examination and polysomnography. There are many complications related to obstructive sleep apnea. Treatments are surgical and non-surgical.
A number of vital tasks carried out during sleep help maintain good health and enable people to function at their best. Sleep needs vary from individual to individual and change throughout your life. Not getting enough sleep can hurt memory performance, health, and your mood.
Insomnia is the perception or complaint of inadequate or poor-quality sleep because of difficulty falling asleep; waking up frequently during the night with difficulty returning to sleep; waking up too early in the morning; or unrefreshing sleep. Secondary insomnia is the most common type of insomnia. Treatment for insomnia include lifestyle changes, cognitive behavioral therapy, and medication.
Fatigue can be described in various ways. Sometimes fatigue is described as feeling a lack of energy and motivation (both mental and physical). The causes of fatigue are generally related to a variety of conditions or diseases for example, anemia, mono, medications, sleep problems, cancer, anxiety, heart disease, drug abuse, and more. Treatment of fatigue is generally directed toward the condition or disease that is causing the fatigue.
Insomnia is difficulty in falling or staying asleep, the absence of restful sleep, or poor quality of sleep. Insomnia is a symptom and not a disease. The most common causes of insomnia are medications, psychological conditions, environmental changes and stressful events. Treatments may include non-drug treatments, over-the-counter medicines, and/or prescription medications.
Hypersomnia is a condition where a person has excessive daytime sleepiness and trouble staying awake during the day. Treatment for hypersomnia includes medication, CPAP machines, and lifestyle changes.
Periodic limb movement disorder (PLMD) is a sleep disorder characterized by rhythmic movements of the limbs during sleep. The movements typically involve the legs, but upper extremity movements may also occur. Movements occur periodically throughout the night and can fluctuate in severity from one night to the next. They tend to cluster in episodes that last anywhere from a few minutes to several hours. These movements are very different from the normal spasms, called hypnic myoclonia, that we often experience initially while trying to fall asleep.
When sleepiness interferes with daily routines and activities, or reduces the ability to function, it is called "problem sleepiness." A person can have problem sleepiness without realizing it. Symptoms of problem sleepiness include: consistently don't get enough sleep, or poor quality sleep, fall asleep while driving, struggle to stay awake when inactive (like watching TV or reading), have difficulty paying attention or concentrating at work, school, or home, have poor performance problems at work or school, have difficulty remembering things, have slowed responses, have difficulty controlling your emotions, and/or if you have to take naps on most days.
Sleep needs in children and teenagers depends on the age of the child. Sleep disorders in children such as sleep apnea, parasomnias, confusional arousals, night terrors, nightmares, narcolepsy, and sleepwalking can effect a child's or teen's sleep. Healthy sleep habits and good sleep hygiene can help your infant, toddler, preschooler, tween, or teenager get a good night's sleep.
Sleep apnea is a disorder characterized by a reduction or pause of breathing (airflow)
during sleep. It is common among adults but rare among children. Although a diagnosis of sleep apnea often will be suspected on the basis of a person's
medical history, there are several tests that can be used to confirm the diagnosis. The treatment of sleep apnea may be either surgical or nonsurgical.
An apnea is a period of time during which breathing stops or is markedly reduced. In simplified terms, an apnea occurs when a person stops breathing for 10 seconds or more.
If you stop breathing completely or take less than 25% of a normal breath for a period that lasts 10 seconds or more,
this is an apnea. This definition includes complete stoppage of airflow. Other definitions of apnea that may be used include at least a 4% drop in oxygen in the blood, a direct result of the reduction in the transfer of oxygen into the blood when breathing stops.